Dressing mechanism for grinding wheels



DRESSING MECHANISM FOR GRINDING WHEELS Filed Nov. 5, 1943 4 Sheets-Sheet 1 hvenior fiamzdms fezih filer/1951.5.

March 19, 1946. r H, N. SEYFERTH I 2,39 ,391

DRESSING MECHANISM FOR GRINDING WHEELS Filed Nbv. s, 1943 4 Sheets-Sheet 2 n rrrr March 19, 1946. v H. N.-$EYFERTH 2,396,891

DRESSING MECHANISM FOR GRINDING WHEELS I Filed Nov. 3, 1943 4 Sheets-Sheet 3 4 52 55 V Y A 1 I [ha 6727507" HaroZdfl/T Ggferfk.

March 19, 194.6. N. SEYFEIRTH DRESSING MECHANISM FOR GRINDING WHEELS Filed Nov. 3, 1943 4 Sheets-Sheet 4 jflorlzgs.

?atented Mar. 119,, 11

itig- SM won Gama; was

nnsssmo l Harold N. Seyferth, East Detroit, ch., assignor to Ex-Cell-O Corporation. Detroit, ltfich... a corporation oi Michigan Application November s. 1942., Serial No. 508,774

mt ttl '7' Claims.

a mechanism embodying a plurality of dressing tools for dressing respective portions 01' the wheel, such as its peripheral edge and flanks, and in which a simple reciprocal slide arrangement serves to actuate all of the tools in timed relation in their respective paths, while afiording independent angular adjustment for the path or paths of the flank dressing tool or tools.

Another object is to prbvide a dressing mechanism of the character indicated which is espe-' cially suited for drlve from a remote point, either by power or by hand crank or the like.

The invention also resides in various improvements in, and novel correlation of, the parts of the mechanism by means of which simplicity and ruggedness of construction, as well as adaptability to a wide variety of'whe'el sizes and shapes, are achieved. I v

Further objects and advantages of the invention will become apparent as the following description proceedataken in" connection with the accompanying drawings in which:

Figure 1 is an end elevation of a dresser mechanism embodying the invention, the same bein shown in conjunction with a portion of a grinding wheel upon which it is adapted to operate.

Fig. 2 is a plan view of the dresser mechanism of Fig. 1, and also includes a fragmentary portion of the grinding wheel. V

Figs. 2a and 2b are fragmentary stop motion views showing, in conjunction with Fig. 2, successive positions occupied by the several dresser points.

Figs. 3, t and are fragmentary detail sectional views taken substantially along the lines 3-3, L-ll and 55, respectively, in Fig. 2.

Fig. 6 is a rear elevation, partially in section, of a dresser mechanism of Figs. 1 and 2.

Fig. 7 is a transverse sectional view taken substantially along the line ll-l in Fig. 2.

Fig. 8 is an exploded perspective view showing various principal parts of the dresser mechanism.

While the invention issusceptible of various modifications and alternative constructions, 1

have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the exemplary embodiment of the invention illustrated in the drawings, the device there shown (see Figs. 1 and 2) embodies three diamond point dressing tools I, II and i2 adapted to dress or true, respectively, the peripheral edge and sides or flanks of a grinding wheel such, for example, as

that designated generally by the numeral l3. In

performing this operation the dresser is adapted to move all three of the tools in? timed relation to each other, each of them being reciprocated in its own individual path. The tool It is reciprocated back and forth across the edge of the wheel to true it to fiat contour, .while the tools Ii and I2 move along angularly related paths to truethe respective flanks of the wheel. As the I prevented by timing the flank dressing tools ii,

I2 so that the one of them toward which the center tool in is approaching is moved away from. such center tool and the other flank dressing tool moved generally toward the center tool. Broadly speaking, the motion of the tools is such that they trail one after another back and forth around the edge of the wheel although each operates on only its own assigned portion of the wheel periphery.

As will hereinafter appear, provision is made for adjustment of the angularity of the paths of the flank dressing tools l I and i2 and the relative positions of all three tools to accommodate wheel peripheries of correspondingly varied contours as, for example, in conditioning the wheel it for grinding threads of diflerent profile.

To support the dresser mechanism as a unitary structure adapted for ready attachment to, or detachment from, the machine, a bracket Hi (Fig. 1) is utilized, the same being secured by bolts It to a portion of the machine bed indicated at I6. The bolts are received in longitudinal slots I5a in. the bracket to accommodate endwise adjustment of the latter. Arcuate bear- I ing members I! (see also Figs.3 and 6)- on the bracket It receive trunnions it which are rigid l3 (see Fig. 8 for detail of shape of the latter),

This trunnion mounting of the support i 3 makes possible angular adjustment of the support about a longitudinally extending axis passing through .the centers of the trunnions, such adjustment being utilized in accommodating the dresser mechanism to wheels of different diameters, as will hereinafter appear. To hold the support IS in various positions of its angular adjustment, locking means is provided for each of the trunnions [8. Such locking means comprises screws 20 (Figs. 1 and 3) passing through holes 2| in:

so that when the latter are tightened, the

trunnions i3 are pulled tightly down against their bearing seats.

Flattened top surfaces l8a on the trunnions 13 support a main slide 24 for reciprocation longitudinally or the support 13 in a path paralleling the axes of the trunnlons l3. Housing blocks- 23, 26 bolted to respective ones of the trunnion faces I 3a are recessed to receive and guide the slide 24. Reciprocation of theslide 24 is effected by means of a screw 21 threaded within an opening 23 in one end of the slide (Figs. 2, 6 and 8), the screw being journaled within the housing 23 and restrained against axial displacement relative thereto. A flexible shaft 29 is attached to the screw- 23, and any suitablereversible means (not shown) may .be used for the dovetail guides 33, mon plane. I

To alter the angularity of the path ofmovement of either of the flank dressing tools Ii or i2, the bolt 31 for its corresponding auxiliary supporting member 35, 36 is loosened and the auxiliary support turned about its pivot 39, 40 t0 the desired angular position. A direct reading of the angular adjustment of each of the flank dressing tools Ii, I2 is aiforded by graduated'scales 42- (Fig. 2) on arms 43 flxedto the housings 25, 26 and overlying the auxiliary slides 32, 33 on which are scribed index lines 44 meeting with the scales. The scales "are concentric with the pivots 39, 43 for the respective auxiliary slide supports.

To reciprocate the auxiliary slides 32, 33 in timed relation with the main slide 24, a cam mechanism for driving the auxiliary slides directly from the main shde is provided. This cam mechanism comprises a cam projection in tegral with the underside of the slide 24 and presenting a flat cam face 45 (Figs. 2, 6 and 8) extending generally transversely of the path of reciprocation of the slide but at an acute angle with respect thereto. An opposed and oppositely angled flat cam face 46- is provided on a block 41 adjustably secured to the recessed underside of the slide 24 by a screw 43 passing through a longitudinal slot 49 in the slide and threaded in a tapped hole in the block. As will be seen such paths lying in a comupon reference to Fig. 2, the cam faces 45, 46

revolving the shaft first in one direction and then in the other to reciprocate the slide. Since the drive is derived by way of a single flexible shaft, the source of power, whether a manually operated device or motor, may be located at any convenient point on the machine, either close to the dresser mechanism or remote from it.

The center dressing tool II is carried by the main slide 24 and thus reciprocated directly by it. For that purpose the tool In is received in a mounting block 33 provided with a dog screw 3| for fixing the tool in various adjusted positions of projection of the same with respect to the mounting block, The block itself is fixed to the intermediate portion of the slide 24.

The two flank dressing tools it and 12 are carried on respective auxiliary slides 32, 33 (Fig. 2) reciprocable along coplanar dovetail guides 34 (see also Fig. 4) fashioned on the upper sides of individual intermediate supporting members 35, 36. The intermediate supporting members 33, 36 project generally laterally outward at one side of the main slide 24 and are individually angularly adjustable on the main support or base iii. For that purpose the intermediate supporting members 35, 35 are pivoted on the main support 13 by bosses 43 on their undersides and which arereceived in depressions 33 in the support l3 (Figs. 4 and 5). Bolts 31 passing through holes 38 centered in the recesses 33 (see Fig. 8) serve to hold the auxiliary slides releasably in their positions of selected angular adjustment. The usual plates 4| (Fig. 4) are provided for securing the auxiliary slides 32, 33 in position on their dovetail guides 34.

The flank dressing tools ll, 12 are adjustably secured within and project laterallyfrom the respective auxiliary slides 32, 33. Accordingly. these tools are moved through straight line paths as their respective slides are reciprocated alon are thus arranged to diverge from each other in a direction opposite to the divergence of the guides 34 for the auxiliary slides 32, 33 so that the guides 34 are approximately normal to their respective cam surfaces.

Coacting with the cam surfaces 45, 46 are cam follower rollers 30, iii journaled on the inner ends of the respective ones of the auxiliary slides 32, 33. The auxiliary slides are yieldably urged outward by compression springs 52 in a direc- 54, outward movement of the auxiliary slides 32,,

33 under theurging of the compression springs being limited by stopnuts 55 threaded on the rods 53. As the main slide 24 reciprocates the followers 5!, 52 are thus constrained to move along the respective inclined cam faces 45, 43. carrying the auxiliary slides 32, 33 with them so that the latter slides areireciprocated reversely with respect to each other and in timed relation with respect to the main slide.

By pioviding the cam face 46 on the adjustable block 41, the spacing between the cam faces 45, 46 may be varied to accommodate adjustment changes in width of the wheel contour or different relative angular positions of the auxiliary slides 32, 33, while still retaining the flank dressing tools ILI. l2 located with predetermined displacements relative to the center dressing tool Ill.

As heretofore indicated, the flank dressing tools H, l2 are 'reciprocated in straight line paths lying in a common plane, and in order that they 7 shall cut straight-sided flanks on the grinding aaeaeer wheel 53 it is requisite that this plane pass through the axis of rotation of the grinding wheel. Location of .this plane is indicated by the line XX in Fig. 1. It is to facilitate retention of that relation, with'changes in wheel diameter, that provision is made\ for angular adjustment of the dresser support It about its longitudinal axis through the use of the trunnions I8 heretofore described. Upon reference to Fig. 1, it will be seen that if the diameter of the wheel I3 is decreased so that its periphery occupies the position indicated by the dot-dash line l3a that the axis of rotation of the grinding wheel will be displaced to the left along the horizontal line L-L if its point of contact P with the work remains fixed. With such change in the location of the wheel axis, it is necessary to turn the dresser support l9 counterclockwise (as viewed in Fig. 1). To facilitate such adjustment a scale 56 may be provided on the end of one of the supporting bearings I! to coact with an index line 5'! scribed on the adjacent trunnion end face and calibrated interms of wheel diameter.

The operation of the disclosed dresser mechanism will, in general, be clear from the foregoing. By way of recapitulation, it may be noted that the angular position of the dresser support I9 is initiall adjusted to accommodate the wheel diameter and the respective angular positions of the auxiliary slides 32, 33 are initially adjusted to conform with the angularity of the flank surfaces to be dressed on the wheel. The projection of the several dresser points fromtheir holders is, also adjusted initially to conform with the wheel contour to be dressed.

Having effected such preliminary adjustments, it is only necessary to revolve the drive screw 2'1! by means of the flexibleshaft 29 first in one direction and then in the other suflicient distances to reciprocate the main slide 24 through a full stroke forward and then back to the starting point in order to operate the dresser. Such reciprocation of the main slide carries the center dressing tool In back and forth across the edge of the grinding wheel, dressing the same. At the same time the cam surfaces t5, 36 on the main slide coact with the cam follower rollers 50, 5| to reciprocate the flank dressing tools I I, l2 reversely with respect to each other and in timed relation with the center dressing tool It. As the center dressing tool moves progressively from the position of Fig. 2 through that of Fig.

.2a to the position of Fig. 2b, the tool ll moves outward of the wheel toward the main slide of the dresser mechanism along its corresponding flank of the wheel, while the other flank dressing tool l2 moves inward in the opposite direction. In the return stroke of-the main slide 2 5 .each of the tools moves reversely, passing suclarly related tothe first-mentioned path, and

means including coacting cam and cam follower elements carried by the first and second slides for reciprocating said second slide in timed relation with reciprocations of the first.

2. A dressing mechanism for grinding wheels comprising, in combination, a support, a plurality of dressing tools and a corresponding plurality of slides carrying the same, means mounting a first one of said slides on said support for reciprocation in a fixed rectilinear path, adjustable means'mounting' a second one of said slides for reciprocation in a path bearing an adjustable angular relation to the first-mentioned path, and means including coacting cam and cam follower elements carried by the first and second slides for reciprocating said second slide in timed relation with reclprocations of the first.

3. A dressing mechanism for grinding wheels comprising, in combination, a support having a main slide reciprocable thereon, a pair of auxiliary slides mounted on'said support for reciprocation in individual paths lying in a common plane and generally angularly related to each other, said paths extending laterally-from one side of the path of reciprocation of said main slide, individual dressing tools carried by each of the aforementioned, slides, and means for adjusting said support angularly about an axis paralleling the path of reciprocation of said main slide.

4. A dressing mechanism for grinding wheels comprising, in combination, a support having a slide reciprocably mountedthereon, a first dressing tool carried by the slide and projecting laterally thereof in a direction generally transverse slides, and means for yieldably urging said cam followers into engagement with respective ones of said cam surfaces.

5. A dressing mechanism for grinding wheels comprising, in combination, a support having a slide reciprocably mounted thereon, a first dressing tool carried by the slide and projecting laterally thereof in a direction generally transverse to the path of reciprocation of such slide, cam means rigid with the slide and presenting a pair of opposed cam surfaces extending angularly across the path of reciprocation of such slide, a

pair of angularly adjustable intermediate supporting members carried by said support, auxiliary slides having individual dressing tools thereon and reciprocably mounted on respective ones of said intermediate supporting members, scale and reference elements on said support and said intermediate slides coacting to indicate the individual angles of adjustment of said intermediate supporting members, cam followers connected to respective ones of said auxiliary slides, and means for yieldably urging said cam followers into engagement with respective ones of said cam surfaces.

6. A dressing mechanism for grinding wheels comprising, in combination, a support having a slide reciprocably mounted thereon, a first dressing tool carried by the slide and projecting laterally thereof in a direction generally transverse to the path of reciprocation of such slide, cam means rigid with the slide and presenting a pair of opposed cam surfaces extending generally angularly across the path of reciprocation of the slide, a pair of intermediate supporting members each having a guideway extending longitudinally of the same, means for pivotally mounting said intermediate supporting members on said support at one side of said slide with said guldeways projecting generally laterally outward from said slide divergently from each other in a common plane, the angles at which said intermediate supporting members project outwardly from said slide being slide reciprocably mounted thereon, a first dress-- ing tool carried by the slide and projecting laterally thereof in a. direction generally transverse to the path of reciprocation of such slide, said slide having a first cam surface thereon of flat contour extending generally transversely across the slide but at an acute angle to the path of slide reciprocation, a cam member having a secand cam surface thereon opposed to the first cam surface and angled away from the same, means for adjustably securing said cam member to the slide with a selectively variable spacing between said opposed cam surfaces, 9. pair of angularly adjustable intermediate supporting members carried by said support, auxiliary slides having individual dressing tools thereon and reciprocably mounted on respective ones of said intermediate supporting members, cam followers connected to respective ones of said auxiliary slides, and means for yieldably urging said cam 

